The regional difference is probably not the problem. I brought my copy directly from United State rather than the "Asian version" (same as those made in Singapore) imported by Microsoft Taiwan.
BTW, I reinstalled my game and tested with 1.0.0.15 exe + 1.0.0.15 esm (US English of course, should be 288,769,595 bytes?) with your Fake Patch (loaded after Fallout3.esm and before Anchorage.esm) plus my pre-1.1 saves & no mod. Unfortunately, the quest script is still not loaded. But with FOSE it works. (I didn't change anything beside loading FOSE.) It seems my assumption is right, it has nothing to do with esm version. It's the exe won't load Anchorage.esm properly. (I can be sure the exe is not corrupt.) May I suggest mentioning my case (the quest can't start, even with console command "startquest dlc02oa1" you'll get the error "Item 'dlc02oa1' not found for parameter Quest") and using FOSE as a problem solver?
Just curious about if using FOSE will effect my saves without any FOSE-dependent mods? (like storing some of its extra variables)
Well, I guess FOSE is the way to go in your case. :shrug: There's everything to gain and nothing to lose for using it standardly, so... All I can say is the 1.0.0.15 .exe is loading O:A fine for me and did for others after adding the O:A archives to their sArchiveList. There
is a tendency for the 1.1.0.35 and 1.4.0.6 .esm's to intermittently behave strangely regarding the mouse upon startup, so I'm sticking with the recommendation of using the matching .exe and .esm, then bridging the gap to 1.4.0.6 with Fake Patch.esm. I'm glad to hear you got O:A up and running, although it's still baffling me that you
need FOSE for O:A to work, but that might have something to do with FOSE disabling Games for Windows LIVE!, which I wouldn't doubt was either directly or indirectly the problem this whole time...
Size: 275 MB (288,769,595 bytes)
Size in disk: 275 MB (288,772,096 bytes)
We've got the same .esm...